Kovalchuk took a pass from defenseman Marek Zidlicky low in the left circle and beat Michal Neuvirth, giving the host Devils a 3-2 victory after they blew a 2-0 third-period lead. Neuvirth finished with 32 saves, including seven in overtime.

“I got a good angle with that shot,” Kovalchuk said. “The key thing was that we all had faith in the overtime.”

Stephen Gionta and Patrik Elias also scored for the Devils, off to their first 3-0 start since the 2002-3 season, the last time they won the Stanley Cup.

Patrice Bergeron, Shawn Thornton and Gregory Campbell also scored for the Bruins (3-0-1). Keith Aucoin had his first career two-goal game for the Islanders (2-2), who played the second of five straight games on the road.

KNUBLE AND FLYERS REUNITE The veteran right wing Mike Knuble returned to the Philadelphia Flyers, signing a one-year contract. He will be available for Saturday’s game at the Florida Panthers.

Knuble, 40, spent the past three seasons with the Capitals. He played for the Flyers from 2005 to 2009, recording 114 goals and 221 points.

A version of this article appears in print on January 26, 2013, on Page D4 of the New York edition with the headline: Kovalchuk’s Overtime Goal Lifts Devils to 3-0; Isles Fall in Boston. Order Reprints|Today's Paper|Subscribe